Just got a 3597LMTHD

Well, I love this GPS. Kind of nice getting in the truck to come home and it tells me right off if there are any traffic alerts or not. It seems to know that I'm going to work in the AM and tells me (without prompting it) how long the drive will be to work. Can't rely on it though, as I'm outside the reception area for traffic updates when I start out.

The only "But" so far is the extremely sensitive screen. Hard to handle it while it's on without my fat fingers accidently triggering something. With the 660, I could turn it on, before going out to the truck, while I loaded up my lunchbox, etc. and then just drop it in a jacket pocket when leaving and then put it in the mount in the truck. Hardly ever accidently triggered anything.

Tried that with a few times with the 3597 and caused all kinds of beeps when I removed it from my pocket. The 3597 boots up so fast and locks on satellites so quickly that I don't need to turn it on in the house.

A side note: In the 18°F temps this AM, I let the GPS snap into it's mount and then tried to adjust the angle. Well, after almost 4 yrs. of attachment to the dash, the mounting disk popped off. I was not happy and then the suction mount wouldn't stick to the windshield (too cold I guess), but it stuck this afternoon when I left work for home, when it was much warmer. A new Beanbag Mount was ordered from Amazon 20 minutes ago and will be here Monday.

Regarding traffic reception. The 2597 is the first GPS I have owned that has it. Is there any rule of thumb as to how far from a station you can be and still receive information? I am assuming it is like receiving a regular FM station. In Wisconsin there are only two places listed, The closest being about 40 miles in a straight line.

You're right at the edge of the reception area I think. Antennae placement is important.

If you have an iphone or an android smartphone, there is a free app that will get the traffic info to the GPS via Bluetooth when you are out of range. Don't know how much that will affect your wireless bill though. Info for app is at Garmin site.

The range for traffic is significantly less than for an FM broadcast station. This type of information is carried over a secondary channel which is limited by FCC rule to be about 10% of the station's primary power. So, a 50,000 watt FM station can have a secondary channel of 5,000 W or less.

Why not just turn it on and then quickly tap the power button to put the 3597 in to "sleep" mode. I've never accidently triggered anything doing that. Once your ready to put the GPS on the mount it will either come on by itself when the mount gets powered or you can just quickly tap the power button again and it's back up and running.

I purchased mine about a week ago from Best Buy. They price matched Amazon and sold it to me for $285. Not a bad deal IMO. So far I have no problems with the unit and absolutely love the drastic improvements over my old Magellin.

I've never had the feature before so if I don't receive it, it wasn't the reason I bought this GPS anyway. I was just curious as to how the feature worked. One other question maybe you can answer. I'm thinking the stations use a standard frequency, would you know what that frequency would be? I have a high end scanner that will pick up any frequency uninterrupted from sub AM broadcast band up to 13 gig. It is hooked up to an outdoor antenna about 35 feet in the air. It might be interesting to see if I could pick anything up.

I have had my 3597 for about 6 months. I love it!, however it doesn't work for my wife because she usually wears Polaroid sunglasses. Now as for traffic...the coverage is very poor on Interstates as they usually wander through open countryside well away from major metropolitan areas. I got very frustrated on a major trip when a warning for an apparent major accident up ahead just dissapeared. I have a cell with data service and purchased Garmins traffic feature for Smartlink. It is very, very good, looks like coverage everywhere I have looked at, It even works in simulation mode. My cell has a data usage monitor and I was very surprised how low the data usage was, well below many other apps (beware of Yelp and auto updates). I can very much recommend it for its few dollar cost. The only drawback that I can see is battery use on the cell, really must have a USB charger in your car for long trips.

HD radio is digital in that it is just a data stream. I'm not that well versed in broadcast but I believe the primary frequency for the station has a portion of its bandwidth set aside for digital carriers. This also assumes you are receiving a standard FM broadcast and not an HD station. Because HD stations are totally digital their signal can only be decoded with a digital receiver which is why you can't hear one on a standard FM radio. Now, how they go about not passing the digital "noise" through a standard FM receiver, I'm not sure but if your scanner receives the signal, it will sound similar to a buzz saw slicing through a plank of wood. The changes in tone is the density of the bits in the data stream so the more changes, the greater audio difference.

Standard FM is a method of transmitting a signal on a base or center frequency in which the frequency shifts or modulates according to the intelligence being carried. Now the amount of deviation from the center frequency is controlled and the amount of allowed deviation is the bandwidth of the signal. If you further reduce the bandwidth (or amount of deviation) you reduce the amount of the authorized bandwidth occupied. This allows a station to broadcast additional information within its allocation on what are subcarriers. It is these subcarriers which operate a reduced power that carry additional information such as song titles, artist and traffic.

Thanks Box Car, I have another scanner that covers digital so I'll have to do a little research

The digital information is on a sub-carrier, which uses the same basic technology that FM stereo uses.

Not only would you need a specifically designed receiver. You would also need a digital decoder for the digital signal plus you would need software to apply it to the map.

I'm sure the GT-60 has the receiver and decoder built into a single chip, else it would not fit into such a small package. Software in the 3597 takes the information and displays it on the map.

I'm sure that there are some fellow Hams out there that would be able to construct a receiver to retrieve the digital info, but is it worth it?

In the US, digital audio is broadcast with HD radio, a tradmark of iBiquity's patented in-band on-channel (IBOC) digital radio technology. This is the only FCC approved technology.

Garmin's HD traffic receivers , such as the GTM-60 sold in the US and Canada decode the traffic information embedded in the HD signal.

I believe the European countries adopted the DAB digital audio standard and Garmin's GTM-70 decodes the European digital traffic signals (?). Need help here from some more knowledgeable.

More information:
HD Radio US/Canada:
http://en.wikipedia.org/wiki/HD_Radio

http://rbr.com/cjsa-fm-launches-canadas-first-hd-radio-stati...

GTM-60:
http://www.poi-factory.com/node/38304

Garmin digital-traffic Europe:
http://www.gpsbusinessnews.com/Garmin-Bets-on-DAB-for-Real-T...

GTM-70
https://buy.garmin.com/en-IE/GB/shop-by-accesories/traffic-r...

You can have both.

See:
http://en.wikipedia.org/wiki/Subcarrier
and
http://en.wikipedia.org/wiki/HD_Radio

These articles get down in the weeds and if a person doesn't understand how AM and FM work, then it may be very hard to understand.

In the second article they mention that "adding" another subcarrier would require "New" equipment to add an additional subcarrier. This may explain why the "Traffic" system is not growing very fast. "New" to me means expensive. Stations probably don't want to lose the HD Radio capability for music or whatever once they commit to and carry the "Traffic" signal.

Did not see any info on the traffic receiver's capability to use the second subcarrier if HD Radio (music) is present on the first subcarrier.